Here is the full list of all 35 Postal III achievements.
Finish your business with Krotchy.
Return Thegways to the owner
Taze 200 victims.
Kill 1000 unarmed bystanders.
Make Venezuela peacemakers go home.
Take out all the criminal scum infesting Catharsis!
Arrest eco zealots leader.
Euthanise 30 elderly folks.
50 kills using cat.
Arrest 200 perps.
50 badgersaw kills.
Beat game with zero kills.n(zombies and bosses don't count)
Kill no animals in one playthrough.
Complete game using only melee.
Complete game using only the pistol.
Complete Good path without falling off.
Complete game killing only males.
Beat the game once. No restrictions apply. Everyone's a winner.
150 kills using fire.
Kill/incapacitate 235 terrorists.
Escape from prison.
Suck up 500 items with the shop vac.
Smash 50 windows.
Destroy 50 cars.
Respawn 20 times.
300 headshot/decap kills.
50 kills using bees.
Spend 900 seconds or more in catnip bullet time.
Injure yourself.
100 kills using machete in melee.
50 kills using boomerang machete.
200 kills using M-60.
Piss 100 gallons of urine.
Choose path for the first time.
Disobey orders, given to you, and see what happens.